In 1982 Bill Chalker was the first civilian researcher to gain direct access to the previously classified RAAF UFO files during several visits to the Canberra headquarters of the Directorate of Air Force Intelligence. He described his access in the following way:

"Prior to 1982 civilian UFO researchers only had a confused and vague picture of clandestine official involvement in Australia. In the face of the lethargy in the RAAFs replies to serious enquiries, I stepped up my efforts at diplomatically trying to get direct access to the RAAF UFO files. It probably surprised me more than anybody elsewhen the RAAF finally agreed to permit me to examine their files.

"The extent of access was unprecedented in the history of the Australian UFO controversy. From the first of my visits to the Russell Offices of the Department of Defence, in Canberra, on January 11th, 1982 to my last in June, 1984, I was able to scrutinise the extent of official UFO investigations in Australia. For the first time a detailed "inside" picture was revealed of RAAF investigations.

"I was able to undertake the first officially sanctioned direct review of the Australian government's UFO files. Over two and a half years I was able to :

(1) examine the majority of the extant UFO files held by the Royal Australian Air Force (RAAF) at the Directorate of Air Force Intelligence (DAFI), Department of Defence, Russell Offices, Canberra (2) examine the entirety of the extant UFO files held by the Department of Aviation at their Bureau of Air Safety Investigation in Melbourne, Victoria.

The review has provided a detailed understanding of official involvement in Australia.

"On Monday morning, January 11th, 1982, I arrived at the Russell Offices of the Department of Defence, in Canberra, to undertake a review of the RAAF/Department of Defence UFO files. This was the first time that a civilian researcher had been afforded this sort of access. For almost thirty years, the RAAF had been the official body invested with the responsibility of investigating reports of UFOs or unusual aerial sighting (UAS) reports in Australia and its territories. Until then no clear and unambigious picture had emerged about the role the RAAF played in the UFO controversy in Australia. Two polarised positions had emerged. The RAAF was covering up its high level involvement in an international "cover-up" of UFO facts, perhaps in concert with the US Air Force. Or, the RAAF was bureaucratically locked into a responsibility it had long since decided was a waste of time, but contined as a service to the general public."

Bill Chalker has undertaken extensive investigations into claims of UFO coverups by the military etc in Australia and the roles played by various government agencies and individuals in governmental, intelligence and military enquiries.

In 1985 in an article in OMEGA Science Digest Bill Chalker revealed the national security implications of a provocative UFO report over the sensitive North West Cape facility that took place on the same day the base was used for issuing a full nuclear alert.

During 1993 he assisted in research for the popular TV programme "The Extraordinary" particularly in the segment featuring the famous radar visual sighting of Naval pilot Shamus O'Farrell.